The invention relates to devices to improve the efficiency of power supplies.
As the source voltage of the power supply and the load on it vary, it is difficult to maintain a specified output voltage without substantial energy dissipation in the regulator. This wastes power and requires substantial overdesign of the regulator to handle the worst case condition. Devices such as autotransformers can vary the voltage of the regulator using a mechanical actuator, but carry penalties associated with mechanical devices. Examples of such devices are shown in U.S. Pat. Nos. 4,063,148; 4,061,958; 3,947,755; 3,913,007; 3,729,673; and 3,651,375.